{“lastseen”:”2025-12-04T20:05:54″,”description”:”## Overview\\n\\nOn December 3, 2025, the React and Next.js teams disclosed a critical security vulnerability (CVSS 10.0), identified as React2Shell, affecting applications that leverage React Server Components together with Server Actions or Server Functions.\\n\\nThe React2Shell vulnerability stems from improper validation of client-supplied data within certain server-side React features. An unauthenticated attacker could exploit this flaw by sending specially crafted requests, leading to unexpected server-side behavior. Successful exploitation could result in unauthenticated remote code execution.\\n\\nThis vulnerability requires no authentication and affects a wide range of modern React\/Next.js deployments.\\n\\n * **Primary CVE** : CVE-2025-55182 (React Core)\\n * **Downstream tracking** : CVE-2025-66478 (Next.js)\\n\\n\\n\\n## What Causes the Vulnerability\\n\\nThe affected functionality involves the mechanism React uses to receive and interpret data for server-side features. Certain malformed or intentionally crafted inputs may trigger unsafe processing paths on the server.\\n\\nThe React and Next.js teams have released security updates that strengthen these validation steps and prevent unintended behavior.\\n\\n## Impact\\n\\nThe vulnerability allows unauthenticated remote code execution (RCE) on servers running React Server Components.\\n\\nApplications using React Server Components are vulnerable even if they do **not** explicitly define Server Function endpoints.\\n\\nIn effect, a malicious actor can send specially crafted requests to a vulnerable server and, due to insecure deserialization of serialized payloads, trigger unintended server behavior including arbitrary code execution.\\n\\nAs of this advisory, there is no evidence of active exploitation in the wild. However, numerous unauthorized or fake proof-of-concept (POC) exploits have been circulated publicly, which may cause confusion or unintended harm if tested without proper validation.\\n\\nAffected Versions:\\n\\n * React: 19.0.0, 19.1.0\u201319.1.1, 19.2.0\\n * js (App Router): 15.x \u2264 15.5.6, 16.x \u2264 16.0.6\\n\\n\\n\\nPatched versions:\\n\\n * React: 19.0.1, 19.1.2, 19.2.1\\n * js: 15.5.7+, 16.0.7+, 16.1+\\n\\n\\n\\n## Imperva Proactive Response\\n\\nImperva\u2019s Threat Research team initiated an immediate investigation to assess the potential impact on customer environments.\\n\\nWithin hours, we:\\n\\n * Analyzed the vulnerability and mapped out the most plausible exploitation paths\\n * Developed and validated virtual patching rules designed to detect and block malicious request patterns associated with the issue\\n * Rolled out these protections automatically across the entire Imperva Cloud WAF customer base\\n\\n\\n\\n**All protections are already active, require no change from customers, and continue to be monitored and refined as new information becomes available.**\\n\\n## Conclusion\\n\\nThis is a significant framework-level security issue affecting widely used technologies. Imperva customers are already protected through our rapid response and proactive security controls. We will continue to track this vulnerability closely and update protections as new information becomes available.\\n\\nWhile Imperva protections mitigate known attack vectors, customers should:\\n\\n 1. Update React and Next.js to the vendor-provided patched versions\\n 2. Review any server-side features that accept data directly from clients\\n 3. Continue monitoring vendor advisories for future updates\\n\\n\\n\\nFor further assistance, please contact Imperva Support or your Customer Success representative.\\n\\nThe post Imperva Customers Protected Against React Server Components (RSC) Vulnerability appeared first on Blog.”,”published”:”2025-12-04T19:03:23″,”modified”:”2025-12-04T19:03:23″,”type”:”impervablog”,”title”:”Imperva Customers Protected Against React Server Components (RSC) Vulnerability”,”source”:””,”references”:””,”id”:”IMPERVABLOG:24C99ED840303E01AC4633745DA94C7E”,”bulletinFamily”:”blog”,”cwe”:null,”cvelist”:[“CVE-2025-55182″,”CVE-2025-66478″],”sourceData”:””,”sourceHref”:””,”cvss”:{“score”:10,”severity”:”CRITICAL”,”vector”:”CVSS:3.1\/AV:N\/AC:L\/PR:N\/UI:N\/S:C\/C:H\/I:H\/A:H”,”version”:”3.1″},”cvss2″:{},”cvss3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””,”cvssV3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””}},”href”:”https:\/\/www.imperva.com\/blog\/imperva-customers-protected-against-react-server-components-rsc-vulnerability\/”,”category_name”:”News”,”post_link”:””,”product”:””,”version”:””,”vendor”:””,”ai_description”:””,”ai_severity”:””,”ai_vendor”:””,”ai_product”:””,”ai_version”:””,”ai_score”:0}<\/p>\n","protected":false},"excerpt":{"rendered":"
{“lastseen”:”2025-12-04T20:05:54″,”description”:”## Overview\\n\\nOn December 3, 2025, the React and Next.js teams disclosed a critical security vulnerability (CVSS 10.0), identified as React2Shell, affecting applications that leverage React…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[9,6,8,36,12,59,13,7,11,5],"class_list":["post-28661","post","type-post","status-publish","format-standard","hentry","category-category_news","tag-critical","tag-cve","tag-cvss","tag-cvss-100","tag-exploit","tag-impervablog","tag-news","tag-security","tag-tapic","tag-vulnerability"],"yoast_head":"\n